As of January, 21 states and the District of Columbia had a minimum wage that was higher than the federal one.

“There is a disagreement at the Fed over how much slack there is in the labor market. What the minimum wage does is complicate their assessment,” said Ann Owen, a professor of economics at Hamilton College.

Minutes of the last Fed policy meeting in April show some Fed officials think the labor market remains weak, needing the central bank to maintain its easy policy stance. Others seem to think it is much healthier, and the central bank should be able to raise short-term interest rates soon.

Fed Chairwoman Janet Yellen told Congress that she generally agreed with a Congressional Budget Office study that an increase in the minimum wage would have positive and negative effects.

Sorting these effects out is very difficult for the central bank, Owen said.

“Changing the minimum wage makes it hard to interpret the data,” she said.

There is general agreement that the minimum wage impact on inflation is not large.

An increase even in the national wage floor would be so small that it is likely not to be “even noticeable at all,” said Catherine Mann, a professor of global finance at Brandeis University.

For one, not very many people earn the minimum wage. The Bureau of Labor Statistics estimates that only 4.7% of the nation’s hourly paid workers receive the federal minimum wage.

Mann noted that the labor share of GDP, or how much of our total income going to workers instead of capital-holders, is now at the lowest level since the 1920s.

“Having that share move towards historic norms might well be a prerequisite for a stronger economy,” Mann said, and an increase in the minimum wage part could help.